Fuel control means



July 5, 193.8. H. c. sHAGALoFF FUEL CONTROL MEANS 1934 3 Sheets-Sheet 2Filed Aug. 21

INVENTOR.

ATTORNEY.

Filed Aug. 21, 1934 3 Sheets-Sheet 3 INVENTQR. f BY f 7 l f? l @AATTORNEY,

Patented .u'ly 5, 1938 FUEL CONTROL MEANS Harry C. Shagalo, Evansville,Ind., assignor, by mesne assignments, to Servel, Inc., Dover, Del., acorporation of Delaware Application August 21,

s` claims.

My invention relates torefrigeration and more particularly to arefrigerator of the absorption type operated by a liquid fuel burner. l

' It is an object of my invention to provide a refrigerator of this typehaving automatic thermostatic control.

Another object is to provide an absorption type refrigerator having afloat regulated liquid fuel burner to whichy the supply of liquid fuelis controlled responsive to the refrigeration temperature.

A further object is to provide an absorption type refrigerator having athermostatically controlled liquid fuel burner adapted to maintain a l54minimum or pilot flame.

Apstill further object of my invention isto pro- ,videy athermostatically,A controlled liquid fuel burner for an absorption typerefrigerator which is not subject to smoking upon s'udden changes in 20the thermostat temperature or adjustment.

Y In aliquid fuel yburner with a float regulated liquid level there is.an appreciable amount of liquid fuel normally contained in the iloatchamber. Itis, therefore, ka characteristic of such a '25 :burnerthatthe. flame slowly diminishes as the liquid level decreases when thefuel supply is shut off. In accordance with vmy invention, I provide `anabsorption type refrigerator heated by a float `regulated liquid fuelburner and, to automatically .30 control the refrigeration temperature,utilize a thermostatically operated valve in the fuel line to theburner, and take advantage of the natural holdover of the burner to keepit ignited while the thermostatic-valve is closed.

.35 Two principal problems are presented in securing satisfactory burneroperation with such automatic control. When the control valve is closedfor an appreciable length of time and the surface level of liquid fuelin the burner decreases,

'im the burner flame becomes unstable and may be'- come extinguished. Imeet this problem by providing a wick extending downwardly below thelevel of liquid in the burner to maintain a flame upon decrease inliquid level. The length of time 'a5 that a flame will be maintained bythis wick is determined by the volumetric capacity of the burner whichmay be increased, for instance, by increasing the size of the floatchamber. By this means, a minimum flame is maintained for auto- 50matlcally relighting the burner when the automatic valve is opened andthe supply of liquid to the burner resumed. The wall of the burnerreceptacle in which vaporization of the liquid fuel occurs becomesheated above the level of liquid 555 fuel :lue to combustion of thevapor when mixed 1934, Serial N0. 740,757

(Cl. S- 38) contactof the liquid with thehot wall ofthe rev ceptacle.This excessive vaporization is `evidenced by an undesirable smoking oftheburner lwhich is due to incomplete combustion of the excess vapor. Itherefore provide a liquid flow restricting means in the fuel line tothe burner, for

instance a capillary tube, to dampen a surge or rapid flow of liquid inthe burner upon rapid operation or-adjustment of the automatic controldevice.

My invention will be more fully understood yupon reference to thefollowing description and the accompanying drawings forming partof thisspecication and of which: y

Fig. l is a broken side elevation, with parts broken away, of arefrigerator embodying my in-4 vention; y

Fig. 2 is a detail view, partly in vertical section, of a liquid fuelburner and control device for the refrigerator shown in Fig. 1;

Fig. 3 is a detail section on line 3 3 in Fig. 2;

Fig. 4 is a detail section illustrating a modification of the apparatusillustrated in the other iigures; and

Fig. 5 is a detail section on line. 5-5 in Fig. 2.

Referring to Fig. 1 of the drawings, a refrigerator cabinet Ill includesa thermally insulated storage compartment II accessible by means of adoor I2, and a lower apparatus compartment I3 accessible by means of adownwardly hinged door I4. An absorption refrigeration apparatus ismounted in the cabinet I0 and includes a cooling element or evaporatori5 in the upper part of the insulated storage compartment II, and agenerator having a substantially horizontal portion I6 in one side ofthe lower apparatus compartment I3. The horizontal portion I6 of thegenerator is provided with a substantially horizontal inner heating iiueI1 extending therethrough and is surrounded by an outer heating ue I8.The outer heating flue I8 is surrounded by suitable thermal insulatingmaterial i9, such as mineral wool, retained in place by a light sheetmetal casing 20. The forward end of the heating'flue I8 projects beyondthe front end of the casing and also beyond the end of the inner ue I1.Beneath the projecting end of the outer heating flue I8 is mounted aliquid fuel burner assembly 2I having partition 33 forming chambers 34and 35,.

la.. i:

a removable cldmney or combustion shield 22 which extends upwardly intothe forwardly projecting end of the outer heating ilue |8 which isprovided with a cutaway portion or recess 23 to admit the upper end ofthe chimney 22'. The forwardly projecting end of the iiue I8 and theupper end of the burner chimney 22 are enclosed by a removable thermallyinsulated hood 24. For a V more complete description of this assembly,reference may be had to an application Serial No.

'734,075 of William R. Hainsworth.

In the other side of the lower apparatus com- -partment I3 is e. storagetank or reservoir 25 for includes a sensitive bulb 29 located in thermalex-v change relation with the evaporator er cooling element |5 or thespace to be cooled and connected to the thermostatic vaive 21 by a smalltube 30.

The path of 'liquid ow from the reservoir to the burner may be betterunderstood by reference to Figs. 2 and 3. In Fig. 2 there is shown, invertical section, only that part of the burner necessary .forexplanation of my invention. The burner and safety valve 3| aredisclosed in more complete detail in said application Serial No.'734,075 of William R. Hainsworth. The liquid fuelsupply line 26 fromthe reservoir is connected to the thermostatically operated valve 21,shown in section in Fig. 3. AThe thermostatic valve 21, as illustrated,comprises a substantially cylindrical-body member 32 having a central Avalve opening 36 in the partition 33 aiords .communication between thechambers 34 and 35. The chamber 34 is closed by a cover e1 and thechamber 35 is closed by a resilient diaphragm 38, secured at itsperiphery between the body 32 of the valve casing and a cover 39. Avalve member 48 in chamber 34 is adapted to cooperate with the valveopening 36 to control ilow of liquid through the latter and isoperatively connected by a valve stem 4|, extending through the vaiveopening 36, to an expansible element such as a bellows 42 in the chamber35 and mounted on the diaphragm 38. The bellows 42 is connected by meansof the small tube 30 to the sensitive bulb 29 on the refrigeratorcooling element, the

bellows 42, tube 30, and bulb 29 forming an expansible fluid thermostatfor operating the valve member 481m control ow of liquid fuel throughthe valve opening 36 responsive to temperature of the refrigeratorcooling element. The thermostat is adjustable by means of a screw 43threaded through the cover 39 into adjustable abutment against theresilient diaphragm 38 on whichl the thermostat bellows e2 is mounted. y

Liquid fuel flows from the reservoir 25 through the supply conduit 26into the chamber 34, and iiow of liquid from the chamber 34 through thepassage 36 into thechamber35 is controlled by the valve member 48. Fromthe valve chaniber 35, liquid fuel ilows through the conduit 28 to anormally open safety valve 3|. 'Ene latter is adapted to be closed uponoverow of liquid from the burner or hazardous increase in temperatureoutside of the burner as described in said application of William E.Hainsworth. After passage through the safety valve 3|, the liquid liowsthrough a conduit 44 toA a chamber 45.

Communication between the chamber 45 and a oat chamber 46 of the burneris controlled by a fioat operated valve 41. In Fig. 2, there appearsonly a portion of the oat chamber 46, which is shown more fully invertical section in Fig. 5. Communication between the float chamber 46and a =chamber 48 is controlled by a mamually adjustable valve 49. Thelower end of a burner tube 5|) is connected to the chamber 68, and theupper end of the burner tube 59 is connected to the lower part of anannular burner vwell 5|. Above the burner well 5| is removably locatedthe burner chimney or combustion shield assembly 22, comprisingperforated cylinders 53 and 54 surrounded by an imperfora-tefrus'toconical shield or chimney 55, the cylinders 53 and 54 and theshield 55 being conoentrically located in spaced relation with respectto each other and secured by mutually perpendicular bars 56 and 51 whichextend through the concentric elements and are retained in position bypins 58 in the Vouter ends thereof.

Flow of liquid fuel from chamber 45 into the iioat chamber 46 isregulated by the iioat valve 41. As may be seen in Fig. 5, the floatchamber 46 includes an elongated passage connecting two float vessels 63and 64. In the latter are eats 65 and 66 from which is suspended a beam61 located in the elongated passage. 'The valve 41 is connected to thecenter ci the beam 61 so as to be operated by the iioats 55 and 66 tocut off ow o'f kerosene intcthe float chamber at a desired liquid levelwhich is thus maintained substantially constant. If, for any reason,this liquid level in the float chamber should rise, liquid wouldoverflow through conduit 62 and cause operation of the safety vvalve 3|to cut off further supply of liquid to the burner. From the. :iioatchamber46, liquid ows past the manually adjustable valve 49 into theehamber 48 and the burner tube. 50. When the burner is lighted, keroseneflows past the valve 49 at aqrate dependent upon the setting of thisvalve. The maximum level of liquid in the burner tube 56 and, therefore,the maximum burner flame depend upon the rate of ow past the valve 49.The valve 49 may therefore be referred to as a maximum flame adjustmentvalve. It will be understood that the valve 49 may be closed to isolate4During operation of the refrigerator, that is,

when the burnerr` is lighted, flow of liquid to the burner is controlledby the thermostatic valve 21 responsive to temperature of, therefrigerator lcooling element I5, as previously described. Thisthermostatic operation of valve 21 aiects the size of the burner flame,within the maximum limit determined by the float valve 41 and manualvalve 49, to maintain the temperature of the cooling element i5substantially constant. If the' temperature of the cooling element i5decreases suiciently to entirely close the thermostatic valve 2?, theburner flame gradually decreases as the liquid level in the floatchamber 48 and burner tube 58 gradually decreases.. In order to increasethe time that the thermostatic valve 21 may 4remain closed withoutcausing the burner ame to go out, I provide a Wick 59 extending from theburner well 5| downwardly into the burner tube 58 so that a llame willbe maintained by supply of liquid fuel through the wick as long as thelevel is above the lower end of the wick. It will be understood that thewick 59 should not obstruct the normal flow of liquid upwardly in the Iburner tube 50. In Fig. '4, I have shown a slight modification inwhich'a separate tube 60 is connected from the burner well l to thelower part of the burner tube 5D and contains a wick 6I which need notextend into the burner tube 5U, and therefore does not interfere withflow of liquid in the burner tube.

During operation with a minimum flame, the upper end of the tube 50 andthe well 5| of the burner become exceedingly heated, and, if liquid issuddenly admitted to the burner after such minimum ame operation,vaporization of liquid in the burner tube 50 and burner well 5l is sorapid that incompletecombustion occurs in the chimney 22, which isevidenced by smoke. Such surge of liquid into the burner might be causedby rapid operation or adjustment of the thermostatic valve 21. Af-terthe thermostatic valve 21 has been closed for an appreciable length oftime, the regulating or float operated valve 41 is open wide, and suddenflow of liquid will cause rapid rise of liquid in the burner tube beforebeing checked by closing of the float valve. In order to minimize suchliquid surge into the burner and the resultant smoking, I provide aliquid ow restricting means in the kerosene supply line to the burner,for instance, by forming conduit 28 with a small internal diameter.Conduit 28 is preferably made small enough to be referred to as acapillary tube. It will be understood that other liquid flow restrictingmeans may be used which permit sufficient flow for high flame so that alimitation is not placed on fiow through valve 49 but which, when thethermostatically operated valve is opened, prevent rapid rise of liquidlevel in the float chamber to restrict the head differential betweenliquid in the float chamber and liquid at the wick. In such anarrangement, pulsations in the flow of liquid` to the burner, which maybe caused bythe rapid operation or 'adjustment of the thermostaticcontrol` valve 21, are dampened by the flow restriction.

Other changes and modifications will be apparent to those skilled in theart wherefore my invention is not limited to that which is shown in thedrawings and described in the specification but only' as indicated inthe following claims.

What I claim is:

1. A liquid fuel burner including a float chamber, a burner well, meansincluding a vertically extending tube having its upper and lower endscommunicating with said burner well and float chamber, respectively, areservoir for liquid fuel, a conduit for conducting liquid from saidreservoir, a valve in said conduit, means including a thermostat foroperating said valve, means connecting said conduit to said floatchamber to provide the only passage for conducting liquid fuel to thelatter and including a capillary passage for preventing liquid surgeupon operation of said valve, a oat operated valve for controllingadmission of liquid fuel to said float chamber responsive to level ofliquid in the latter, and a wick in said burner well having at least aportion thereof in the path of flow of liquid in said tube formaintaining a ame upon decrease in level of liquid in the latter.

2. A liquid fuel burner comprising a burner well, a float chamber, afirst iiow passage communicating with said burner well and floatchamber, respectively, for conducting liquid fuel from said floatchamber to said burner well and including a vertically extending tubehaving its upper end communicating with said burner well, a second flowpassage including a conduit for conducting liquid fuel from a source ofsupply to said float chamber, a valve in said conduit, means including athermostat for controlling said valve, the portion of said conduitbetween said valve and said float chamber providing the only passage forconducting liquid fuel to the latter,

a float operated valve responsive to the level of liquid fuel in saidfloat chamber for controlling the admission of liquid fuel into thelatter, a float in saidfloat chamber for actuating said float operatedvalve, a wick in said burner well having at least a portion thereof inthe path of flow of liquid fuel in said tube for maintaining the flameafter a drop inthe level of the liquid fuel in said burner well, saidfloat and float chamber being constructed and arranged to provide a headof liquid fuel affecting flow to the burner Well, and flow restrictingmeans in said second passage constructed and arranged to allow flow forhigh flame and, when the thermostatically operated valve is opened-toprevent rapid rise of liquid level in the iioat chamber to restrictthe'head differential between liquid in the float chamber and liquid atthe wick.

3. A liquid fuel burner comprising a burner well, a float chamber, meansincluding a vertically extending tube having its upper and lower endscommunicating with said burner well and float chamber, respectively,said tube providing a passage for conducting liquid fuel from said`float chamber to said burner well, means including a conduit forconducting liquid fuel from a source4 of supply to said float chamber, avalve in said conduit, means including a thermostat for controlling saidvalve, the portion of said conduit between said valve and said floatchamber providing the only passage for conducting fuel to the latter andincluding a capillary passage for dampening pulsations in the ow ofliquid fuel therethrough, a float operated valve responsive to the levelof liquid fuel in said oat chamber for controlling the admission ofliquid fuel into the latter, and a wick in said burner well extendingdownwardly in said tube for maintaining the flame after a drop in thelevel of liquid fuel in said tube, said wick being of such size that thenormal flow of liquid fuel through said tube is not obstructed.

HARRY C. SHAGALOFF.

